This invention relates to monitoring the configuration of component feeders on a component placement machine.
Component placement is one of the most labor and data intensive operations in electronic board assembly. Current high speed component placement equipment can place up to 10,000 to 30,000 components per hour, depending on configuration, and can carry up to 1,000,000 or more individual components.
Surface mount components are typically supplied by component vendors as rolled tapes of components that must be loaded onto individual feeders, sometimes called component dispensing cartridges, that can then be mounted in corresponding feeder slots on the machine. These rolls of components (up to, in some cases, 10,000 or more components per roll) may be loaded onto the feeders either at a stock room or at the machine, and the loaded feeders then loaded into feeder slots.
Component placement machines can have many feeder slots (e.g., 150 or more), each accessible by a placement turret or other picking mechanism that picks individual components from the feeders in the slots and places them in particular locations on a printed circuit board, according to programmed instructions. For application flexibility, each feeder and slot is generally constructed to be compatible with many different components.
The physical arrangement of components, feeders and slots must be in accordance with the expected arrangement as programmed in the machine. Any error in the arrangement can cause a corresponding error in the placement of components on the board. In a high volume, low mix manufacturing environment, a component loading error can produce a high number of defective printed circuit boards in a short period of time. In a low volume, high mix environment the chance of component loading error increases because of frequent feeder manipulation for product change over.
To help eliminate loading errors, some have suggested placing bar code labels on individual feeders and slots and then scanning the feeder and slot labels with a hand-held scanner as the feeders are placed in the slots (i.e., before the machine begins its operation).